This invention relates to an article stopping apparatus and particularly to such an apparatus for receiving a series of overlaying and overlapping sheet-like articles and stopping movement of successive articles to form a gap between successive batches or groups of the articles.
In the processing of sheet-like members, a web is sequentially cut into a series of sheet-like members for subsequent processing. In many in-line processes, the sheets are assembled in a continuous line of overlapping sheets with each of the following cut sheets moved into overlapping engagement with the preceding downstream sheet, generally referred to a shingling process. The shingled sheets may be divided into sequential batches for providing a precise number of sheets assembled to a suitable stacking apparatus. In the forming of batches, various systems have been proposed including a stopping apparatus for progressively slowing down and generally stopping the sheet at the upstream end of a batch and progressively stopping subsequent sheets with an increased overlap of succeeding sheets to provide a concentrated group of the sheets with the increased overlap which are then rapidly fed from the stopping apparatus as at least a part of a batch to a stacker or other processing mechanism or apparatus.
For example, the stepping apparatus may include an overlying member which is moved downwardly and progressively into abutting engagement with the incoming stream of shingled sheets on the conveyor thereby stopping the feed of the downstream sheet on the conveyor while allowing the controlled and partial increased movement of the upstream sheets over the conveyor to increase the overlap prior to terminating of their movement and thereby defining the leading end of a batch. Once a selected gap is created with respect to a preceding batch, the overlying stopping member is raised and sheets are released and the batched sheets are allowed to rapidly move from the stopping apparatus. As the leading sheet of the new batch approaches the discharge end of the apparatus, the overlying member again moves downwardly into engagement therewith to prevent its continuous movement and the apparatus again recycles to effect the desired increased overlapping within the next batch in the forming of a new batch.
U.S. Pat. No. 3,337,666, which issued Mar. 19, 1968 discloses a similar means in combination with means for holding of the articles in spaced relation to the conveyor to assist in the batching process.
These and other patents disclose various batching systems generally using some form of a mechanical stopping mechanism. The mechanism which holds the shingled sheets in a retarded position on the conveyor of course are subject to relative movement between the sheets and the conveying mechanism. This may be undesirable in certain applications particularly those where the underside of the sheet can raise printed matter or other matter which might be subject to damage by the relative motion. Further, such mechanical devices rely on a mechanical interengagement generally with the leading edge of the sheet and require relatively complex mechanisms which are subject to various maintenance cost and mechanical failures.
There exists a need for an improved system for holding of the shingled sheets in appropriate fashion to allow the increased overlapping with a minimum complexity of apparatus and yet which operates at high speed with reliable stopping of the sheets and which is particularly adapted to in-line processing of the sheets.